counter rotating - port or stbd?

[Mollers]

Originally Posted by Downhilldai

I've heard it all now....

If you run 'em, it'll bollox the gearboxes on both engines. I made that £1100 mistake once. The bearing carriers will only carry load in one direction.
Swapping the props might help.

[Downhilldai]

Originally Posted by Mollers

If you run 'em, it'll bollox the gearboxes on both engines...

Yes - I don't dispute that one bit.

Just can't believe they bought the story from the apprentice who rigged the motors and claimed that they were fitted with those props when they were delivered

Originally Posted by Mollers

..I made that £1100 mistake once...

I'm really sorry to hear that

Originally Posted by Mollers

Swapping the props might help.

As long as you reverse the gearchange linkages in the control boxes too.

[Mollers]

Originally Posted by Downhilldai

As long as you reverse the gearchange linkages in the control boxes too.

Only if close quarter handling is a concern.

[r mcdonald]

On light twin engine aircraft with counter rotating engines that both turn inwards.
the downward moving blade creates more thrust. So when one engine fails, the thrust from the downward moving blade is closer to the centre of the aircraft, reducing the asymetric effect, so less rudder is needed to keep the aircraft going straight.
Not all twins have counter rotating engines.
rm

[The Garfish]

Originally Posted by Mollers

Only if close quarter handling is a concern.

inn de troo spirrit ov innvestigativ jornalizm, i an i smels a storey.


spil de beens yew cawnegian nobwangir

garF

[Simon B]

Originally Posted by r mcdonald

On light twin engine aircraft with counter rotating engines that both turn inwards.
the downward moving blade creates more thrust. So when one engine fails, the thrust from the downward moving blade is closer to the centre of the aircraft, reducing the asymetric effect, so less rudder is needed to keep the aircraft going straight.
Not all twins have counter rotating engines.
rm

Now this answers my earlier question.

Originally Posted by BogMonster

By the time the props touch the water on a plane you have usually got bigger problems to worry about

Remind me not to charter aircraft in the Falklands, their views on basic principals appear to be well err...very, very basic!!

[Nos4r2]

Originally Posted by Simon B

Remind me not to charter aircraft in the Falklands, their views on basic principals appear to be well err...very, very basic!!

Can't knock it for accuracy though

[Simon B]

Absolutely not Nos!

I've got a thing about knockers...

[PeterM]

I thought that in the light twin ( aircraft) its more to do with airflow hitting one side of the rudder (as it scorkscrews on leaving the porp) & 'pushing' the tail round - some of the older twins if the 'wrong engine' goes on takeoff you are only going one way - down and left , or is that right ?

You can see the effect in water jets - the shaft of water trying turn after leaving the jet.

[r mcdonald]

Originally Posted by Blackroady

I thought that in the light twin ( aircraft) its more to do with airflow hitting one side of the rudder (as it scorkscrews on leaving the porp) & 'pushing' the tail round - some of the older twins if the 'wrong engine' goes on takeoff you are only going one way - down and left , or is that right ?

You can see the effect in water jets - the shaft of water trying turn after leaving the jet.

If both engines turn in the same direction, if the engine that fails is the one that is turning towards the the fuslage. The engine that is still operating and producing alot more thrust on the downward moving blade is further from the centre line of the aircraft, it will need more rudder(and create more drag) to keep the plane staight. so climb performace will not be as good due to more drag.
On single engine aircraft, the prop wash does hit the vertical stabilizer and rudder on one side more than the other. So at high power settings(take off, climbing) right rudder is needed to keep the aircraft staight.
some light twins will not climb very well (or at all)at full weight on a hot day
regards
rm

[PeterM]

Thanks RM - thats why I dont have twin rating - too complicated fro my brain to deal with !